Design Entities for High Speed Design

Before creating High Speed designs in eCADSTAR, design entities should be defined and created. These allow you to use the High Speed functionality, and in some cases are a requirement. These include the following.

• Buses
• Differential Pairs
• Rule Stacks
• Pin Pairs
• E-Nets
• Topologies
• Skew Groups

Figure 1: Design Entities for High Speed Design

Note that the following design entities rely on others to have been created first.

• Skew Group: buses, E-Nets and Differential Pairs must have been created first.
• Topologies: E-Nets, and Differential Pairs must have been created first.
• Buses: E-Nets must have been created first.

Figure 2: Relationship Between Design Entities

In the next task, you will define the buses and Differential Pairs that are required for the supplied DDR2 design.